Don't do this at home, kids

Wisconsin has little in the way of mountains. So this has limited application here.

But Tour de France riders take note:

Viagra improved the cardiovascular and exercise performance of trained cyclists exercising at a simulated altitude of 12,700 feet, according to a study.

The study involved 10 cyclists who collectively improved the time it took to cover six kilometers by 15%, compared with a placebo.

But the improvement mainly was due to four cyclists who improved an average of 39%, compared with six non-responders who improved an insignificant 1%.

The results suggest that the responders had a greater degree of constriction in the blood vessels of their lungs at altitude and therefore benefited from the drug???s ability to relax those vessels.

Viagra is used to treat erectile dysfunction and was originally developed as a high-blood pressure drug.

"(Viagra) could be considered as a treatment for those who suffer most at altitude, but because of side effects that can include severe headaches and the apparent inability to help some people, it should not be taken as an exercise aid by everyone," co-author Anne Friedlander of Stanford University, said in a statement.